Hi,

If I am writing a database library such as DSL, Data Service Layer, there is a need for me to do a good clean up for the connections/results sets/transactions that this library is currently handling.

How ever, if another library/package somewhere else calls for a


java.lang.Runtime#public void addShutdownHook(Thread hook)


How do code or what library to use?

can someone please provide a simple working D example for try out.

Of cause, in Even in Java there is event if some cleaning lady were to accidentally unplug the main socket of your server. :)


-- 
Matthew Ong
email: ongbp@yahoo.com

http://www.digitalmars.com/d/2.0/class.html#StaticDestructor

-Steve

On 5/25/2011 11:13 PM, Steven Schveighoffer wrote:
> http://www.digitalmars.com/d/2.0/class.html#StaticDestructor
>
> -Steve

Static Destructor maybe executed when the class is being unloaded GC?
Because this is a class level. It is more like the application level exit and such.

That is not really the same as:
http://download.oracle.com/javase/1.4.2/docs/api/java/lang/Runtime.html#addShutdownHook%28java.lang.Thread%29


This is triggered when:
# The program exits normally, when the last non-daemon thread exits or when the exit (equivalently, System.exit) method is invoked, or

# The virtual machine is terminated in response to a user interrupt, such as typing ^C, or a system-wide event, such as user logoff or system shutdown.



-- 
Matthew Ong
email: ongbp@yahoo.com

On 05/25/2011 08:35 AM, Matthew Ong wrote:
> On 5/25/2011 11:13 PM, Steven Schveighoffer wrote:
>> http://www.digitalmars.com/d/2.0/class.html#StaticDestructor
>>
>> -Steve
>
> Static Destructor maybe executed when the class is being unloaded GC?
> Because this is a class level. It is more like the application level
> exit and such.

There is a problem at Digital Mars's site. Steve must have meant the module static destructor. Search for "Static Construction and Destruction" on the module page:

  http://www.digitalmars.com/d/2.0/module.html

(Do not click StaticDestructor at the top of the page. That is linked to the class page.)

Ali

On Wed, 25 May 2011 11:35:51 -0400, Matthew Ong <ongbp@yahoo.com> wrote:

> On 5/25/2011 11:13 PM, Steven Schveighoffer wrote:
>> http://www.digitalmars.com/d/2.0/class.html#StaticDestructor
>>
>> -Steve
>
> Static Destructor maybe executed when the class is being unloaded GC?
> Because this is a class level. It is more like the application level exit and such.

This is *exactly* what static destructors do.

"A static destructor gets called on program termination"

Actually, that description is inaccurate for non-shared static dtors, someone should fix that.

> That is not really the same as:
> http://download.oracle.com/javase/1.4.2/docs/api/java/lang/Runtime.html#addShutdownHook%28java.lang.Thread%29

If you want a static dtor that runs on every thread shutdown, use a normal static dtor.  If you want one that runs on the entire application shutdown, use a shared static dtor.

-Steve

On Wed, 25 May 2011 11:50:16 -0400, Ali Çehreli <acehreli@yahoo.com> wrote:

> On 05/25/2011 08:35 AM, Matthew Ong wrote:
>> On 5/25/2011 11:13 PM, Steven Schveighoffer wrote:
>>> http://www.digitalmars.com/d/2.0/class.html#StaticDestructor
>>>
>>> -Steve
>>
>> Static Destructor maybe executed when the class is being unloaded GC?
>> Because this is a class level. It is more like the application level
>> exit and such.
>
> There is a problem at Digital Mars's site. Steve must have meant the module static destructor. Search for "Static Construction and Destruction" on the module page:
>
>    http://www.digitalmars.com/d/2.0/module.html
>
> (Do not click StaticDestructor at the top of the page. That is linked to the class page.)

Oh, yeah, that's exactly what I did!  hm...

Need to file a bug. (filed as http://d.puremagic.com/issues/show_bug.cgi?id=6055 )

Note that class static dtors are exactly the same as module static dtors, they just are inside the class namespace.

-Steve

On 5/25/2011 11:52 PM, Steven Schveighoffer wrote:
>
> If you want a static dtor that runs on every thread shutdown, use a
> normal static dtor. If you want one that runs on the entire application
> shutdown, use a shared static dtor.
>
> -Steve
Module Destructor: Cool feature that I can consider to use for other purpose.

>If you want one that runs on the entire application shutdown, use a >shared static dtor.
It is more like an entire application shutdown event. So I will be placing that at the same module dtor and file as the main(string[] args)
using template mixin.

That might work. I will test that out.

-- 
Matthew Ong
email: ongbp@yahoo.com

On Wed, 25 May 2011 11:52:14 -0400, Steven Schveighoffer <schveiguy@yahoo.com> wrote:

> On Wed, 25 May 2011 11:35:51 -0400, Matthew Ong <ongbp@yahoo.com> wrote:
>
>> On 5/25/2011 11:13 PM, Steven Schveighoffer wrote:
>>> http://www.digitalmars.com/d/2.0/class.html#StaticDestructor
>>>
>>> -Steve
>>
>> Static Destructor maybe executed when the class is being unloaded GC?
>> Because this is a class level. It is more like the application level exit and such.
>
> This is *exactly* what static destructors do.
>
> "A static destructor gets called on program termination"
>
> Actually, that description is inaccurate for non-shared static dtors, someone should fix that.
>
>> That is not really the same as:
>> http://download.oracle.com/javase/1.4.2/docs/api/java/lang/Runtime.html#addShutdownHook%28java.lang.Thread%29
>
> If you want a static dtor that runs on every thread shutdown, use a normal static dtor.  If you want one that runs on the entire application shutdown, use a shared static dtor.

I should clarify that when I wrote this, I thought the description was from the module.html file, not the class.html file.  Ali pointed out the bug in the web site.  So I didn't get why you were talking about classes, sorry :)

Class and module static ctor/dtors should be exactly what you are looking for.

-Steve

On 5/25/11, Steven Schveighoffer <schveiguy@yahoo.com> wrote:
> If you want a static dtor that runs on every thread shutdown, use a normal static dtor.  If you want one that runs on the entire application shutdown, use a shared static dtor.

I saw some commits change a static dtor to a shared static dtor and wondered what was that all about..

On 5/26/2011 12:23 AM, Andrej Mitrovic wrote:
> On 5/25/11, Steven Schveighoffer<schveiguy@yahoo.com>  wrote:
>> If you want a static dtor that runs on every thread shutdown, use a normal
>> static dtor.  If you want one that runs on the entire application
>> shutdown, use a shared static dtor.
>
> I saw some commits change a static dtor to a shared static dtor and
> wondered what was that all about..
Thanks a lot for the all the comments and instructions shown here.

-- 
Matthew Ong
email: ongbp@yahoo.com